At Paul Fraser Collectibles, we've looked at a number of classic cars which were built specifically to challenge Ferrari's seemingly unshakable dominance on the European race circuits of the 1960s.
Of these, the stand-out is the ultra-rare 1963 Aston Martin DB4 GT Superleggera, of which only six were built to GT Lightweight specification.
The most powerful British car of its era, it proved itself against Ferrari on race circuits all over the world, with legends including Stirling Moss and Jim Clarke behind the wheel.
Another exceptionally rare and highly collectible example is the ATS (Automobili Turismo Sport) 2500 GTS, manufactured and raced by Carlo Chiti and Giotto Bizzarrini in direct competition with their former employee, Ferrari.
Only eight examples of the ATS 2500 GTS were ever made, between 1962-65.
However, neither of these rivalries were as intense as the opposition between Shelby Cobra and Ferrari in the mid-1960s.
This fascinating and brilliantly made documentary tells of the strong competition between two men: Carroll Shelby and Enzo Ferrari.
And their rivalry went beyond a desire to win the Championship: it was personal.
As the video explains, Enzo Ferrari would often create tensions within his own racing team, playing his drivers off against each other to encourage them to take terrible risks on the circuit.
The era was already an exceptionally dangerous time for racing, and the Ferrari team endured more than their fair share of casualties.
Many of these casualties were racing friends of Carroll Shelby - and he held Enzo Ferrari personally responsible.
The above video tells the story of how this bitter enmity lead to the creation of what is, according to many, America's greatest ever race car: the Shelby Cobra Daytona Coupe.
It goes some way to explaining the engineering obstacles Shelby's team faced, in a bid which eventually saw them triumphantly beat Ferrari for the 1965 World Championship.
Today, the legacy of the 1965 Shelby Daytona is still felt among collectors. It sold at The Monterey Sports and Classic Car Auction in August 2004, for $280,500.
And other historic Shelbys will be hitting the auction block in the coming months.
The one-of-a-kind 1964 Shelby Cobra 427 Prototype s/n CSX 2196 - nicknamed "The Flip-top" - will hit the sales block at RM's Automobiles of Arizona event on January 22.
Around the same time, also in Arizona, an original 1963 289 Shelby Cobra, CSX2091 and the first production 1966 Shelby GT350 will sell at Barrett-Jackson's 39th Collector Car Auction on January 18-24.